1. Field of the Invention
The present invention relates to a system for delivering interactive information services, such as video, audio, library, interactive games, and the like to a plurality of subscribers. More particularly, the invention relates to a system for transmitting a multimedia signal and interactive data from a service provider to subscribers with different types of subscriber terminals.
2. Description of the Background Art
Recent advances in digital signal processing techniques and, in particular, advancements in digital compression techniques, have led to a plethora of proposals for providing new digital services to a subscriber""s home via existing telephone and coaxial cable networks. For example, it has been proposed to provide hundreds of cable television channels to subscribers by compressing digital video, transmitting the compressed digital video over conventional coaxial cable television cables, and then decompressing the video at the subscriber""s set top terminal. Another proposed application of this technology is a movie-on-demand video system in which a subscriber communicates directly with a video service provider via telephone lines to request a particular video program from: a video library and the requested video program is routed to the subscriber""s home via telephone lines or via the coaxial television cables for immediate viewing. Other proposed video-on-demand systems use a frequency multiplexing technique to enable control information for a set top terminal to be transmitted through a cable network back to an information server. Such a system permits bi-directional communication over a single network.
In each of these information distribution systems, menus are displayed upon the subscriber""s television and using a remote control device, a subscriber selects a desired program for viewing. A program code is then sent from the set top terminal through the communication system back to the service provider. The selected program is then recalled from memory by the service provider equipment and broadcast to the set top terminal that requested that information. Alternatively, the subscriber may telephone the service provider and request certain information that is displayed in a menu upon the subscriber""s television or the subscriber""s set top terminal or the television set may automatically tune, in response to the menu selection, to a broadcast channel to receive information transmitted on that channel.
An important problem in the currently available systems is that they generally provide interactive support for only one type of set top terminal. For example, a system may provide interactive support only for a type of terminal which is manufactured by General Instruments. Another system may provide interactive support only for another type of terminal which is manufactured by Scientific Atlanta, where the Scientific Atlanta terminal has various characteristics that make it incompatible with the General Instruments terminal. This problem of supporting only one type of terminal leads to various disadvantages. For example, to deploy the currently available systems, all set top terminals must be changed to that one type in order to be capable of receiving the interactive support. This is costly and also limits consumer choice of set top terminals. Alternatively, multiple information distribution systems may be developed and deployed, one for each type of set top terminal. This would also be costly. In addition, such multiple systems would not provide the same look and feel to users having different types of set top terminals.
The disadvantages heretofore associated with the prior art are overcome by the present invention. The present invention comprises a multimedia stream incorporating interactive support for multiple types of subscriber terminals. The multimedia stream is created by multiplexing several component streams. The component streams include a video stream, an audio stream, and an interactive data stream. The interactive data stream includes data specific to different types of subscriber terminals multiplexed together.
The present invention also comprises a method for providing interactive support to multiple types of subscriber terminals. The method includes the steps of: (a) providing an input generic definitions of screen objects and control data relating to the screen objects; (b) providing a first set of rules including modifications to the screen objects specific to a first type of subscriber terminal; (c) providing a second set of rules including modifications to the generic screen objects specific to a second type of subscriber terminal; (d) modifying the generic definitions by applying the first set of rules to generate a first output file specific to the first type of subscriber terminal; and (e) modifying the generic definitions by applying the second set of rules to generate a second output file specific to the second type of subscriber terminal.
The present invention further comprises a system for distributing video data while providing interactive support to multiple types of subscriber terminals. The system includes: (a) a source of video data to be distributed to a first subscriber with a first type of subscriber terminal and a second subscriber with a second type of subscriber terminal; (b) a source of interactive data to be distributed to the first and second subscribers; (c) a transport processing multiplexer for multiplexing the video data and the interactive data to generate a transport stream; and (d) where the interactive data comprises (i) a first interactive data specifically modified for use with the first type of subscriber terminal and (ii) a second interactive data specifically modified for use with the second type of subscriber terminal.
An advantage of the present invention is that only one multimedia stream is required to support multiple types of subscriber terminals on the same distribution network. Another advantage is that the support of multiple types of subscriber terminals is done in a way which facilitates giving users the same look and feel across the different types of subscriber terminals.